Regenerative refrigerating system



Jan. 31, 1933. e. F. ZELLHOEFER 1,895,693

REGENERATIVE REFRIGERATING SYSTEM Filed Aug. 6, 1930 2 Sheets-Sheet 1 INVENTOR 262M D -m.

U TTORNEY Jan. 31; 1933. G, ZELLHQEFER 1,895,698

REGENERAT IVE REFRIGERATING SYSTEM Filed Aug. 6, 1950 2 Sheets-Sheet 2 INVENTOR I G'LENA/F-ZELLHOEFEIQ BY M ATTORNEY in side elevation.

Patented Jan. 31, 1933 UNITED STATES GLENN I. ZELLHOEFER, OF BLOOMINGTON, ILLINOIS I REGENERATIVE REFRIGERATING SYSTEM Application filed August 6, 1930. Serial No. 473,486.

This invention refers to improvements in refrigerating systems and more particularly to a system adapted for domestic purposes of the regenerative absorption type.

It is an object of this invention to provide a refrigerating system of this type which is of simple construction, with few parts to get out of order, positive in operation, and inexpensive to manufacture.

' With these and other objects in view reference is made to the accompanying sheets of drawings which illustrate a preferred embodiment ofthis invention with the understanding that detail changes may be made without departing from the scope thereof.

In the drawings:

Fi re 1 is a diagrammatical view illustrating 1: e various elements or parts of the system. and connections in front elevation.

Figure 2 is a top plan view of the heat exchanger with the covering of insulation indicated in dot and dash lines.

Figure 3 is an enlarged detailed view of the solvent pump partly in section and partly Figure 4 is a fra entary view similar to Fi re 1 of a modi ed form. igure 5 is an enlarged detail view partly in section of the valve employed in Figure 4. While the embodiment of this'invention as illustrated upon the drawings is a preferred means for one, it is to be understood that other refrigerants and other solvents as well as other roducing heat in the solution tank, such as hereinafter referred to, may be em loyed.

his improved system includes a cooling unit C, preferably locatedin the cooling compartment of an Ice box or refrigerator, the walls of which are indicated by the reference numeral 1; a heat exchanger H, preferably located in a compartment provided therefor and se arated from the other compartments in the ttom of the refrigerator; and a solvent pump P and, an absorber A, the latter two elements being located either upon the back of the refrigerator 1, or within a compartment provided therefor upon the interior thereof.

The refrigerant is one that is in gaseous form at atmospheric pressure and temperature and the solvent is a liquid which will readily absorb the gaseous refrigerant at the atmospheric pressure and temperature and expel the refrigerant when the temperature of the solution is raised preferably to a temperature of about 275 F. The preferred solvent employed in this embodiment of the invention is tetrachlorethane and the refrigerant methyl chloride.

In tracing the cycle of operation it is thought that it will be better understood if the description begins with the treatment of the saturated solution of the solvent and refrigerant commonly known as strong liquor.

A tank or still 2 is provided to receive and heat the saturated solution, and is preferably surrounded by a body of heat insulating material, said tank preferably having a restricted upward projection 33, as shown. An electric heating element 4. in this form of this invention. is preferably located between the bottom of the solution tank 2, and the surrounding insulation. This heating element is connected to the commercial electric light circuit through a thermostatically operated switch 5, of commercial type, operated by pressure created within a bulb 6, located within or adjacent the solution tank and surrounded by the insulating material, the bulb being connected by a tube to the operating mechanism of the switch whereby the switch is responsive to temperature changes within the solution tank and may be adjusted to break the circuit to the electric heater when the temperature thereof reaches 285 F., and close the circuit when the temperature descends to 275 F.. these temperatures being approximately and being predetermined as desired.

In this particular instance the temperatures specified are those between which the saturated solution of methyl chloride in tetrachlorethane will expel the methyl chloride in the form of a vapor from the top of the solution tank or still. The vapor of the refrigerant is conducted from the restricted portion 3 of the solution tank by a pipe 7, to the interior of a water jacketed receiver or condenser 8, wherein the vaporous refriger- C, absorbing heat from the atmospheresurrounding the unit, and is conducted therefrom through pipe 11, to the bottom of the absorber A. The absorber is preferably in the form of a water jacketed elongated vertical tank or tube containing the liquid solvent wherein the gaseous refrigerant in passmg upward through the solution is absorbed and the saturated solution transferred to the solution tank by the solution pump. It is preferable to arrange a perforated plate 26 within the absorber between the openings of pipes 11 and 16 thereinto for diffusing the gaseous refrigerant as it enters the solution from pipe 11. I

The solution pump is a. receptacle adapted to'contain the hquid solution and is provided with a float 12for controlling the operat1on of the valves 13 and 14, hereinafter described. The bottom of the chamber or receptacle of the pump P is connected by pipe the interior of the pump chamber.

tenor of the upper end of the pump cham-.

15 communicating with a pipe 16 leading from the absorber A adjacent its lower end and the heat exchanger pipe 16 is provided with check valves 17 and 18 between the pipe 15 and the absorber and between the pipe 16 and the heat exchanger respectively. The

heat exchanger comprises two coils of pipe,

surrounding the solution tank or still and imbedded in the surrounding insulation material. The larger outer coil 19 of the heat exchanger is connected to the pipe 16 and discharges strong liquor into the top of the solution tank. The upper end of the smaller coil 20 extends through the top of the solution tank into the interior thereof and terminates adjacent its bottom. The lower end of the smaller coil 20 is connected by a pipe 21 to a nozzle 22 extending within the interior of the upper end of the absorber A. The restricted portion 3 of the solution tank wherein the vaporized refrigerant collects under pressure is connected by a pipe 23 passing through valve 13 to the upper portion of the solution pump P, communicating with The inber is connected by a pipe 24 passing through the valve 14 and through the upper wall of the absorber A and then extends downwardly and terminates at a point above the connection of the absorber with the pipe 16. This pipe 24 is provided with a small orifice 25 in one side thereof just after the pipe passes through'the wall of the absorber.

Valves 13 and 14 are preferably solenoid operated valves which are controlled by an P are so located that when solution is admitted to the absorber A it will also enter the pump chamber of the pump P through connections 15 and 16 and will seek the same level in both the pump chamber and absorber and the relative positions of the pump and absorber are such that as the solvent reaches a level approximately two-thirds of the length of the absorber from its bottom the float 12 in the pump P will begin to rise.

The cycle of operation has heretofore been traced from the solution tank 2 through the whereby the weak liquor is sprayed into the absorber A above the level of the solution therein so any particles of the gaseous refrigerant be successful in bubbling through the solution it will be caught in the spray and or condenser 8, expansion valve 10,

absorbed. As heretofore stated as the level of the solution in the absorber rises the float 12 in the pump P also rises and actuates the switch to open the valve 13 in the connection to the chamber 3 and close the valve 14 in the connection to the absorber A, thus increasing the pressure within the pump chamber above the level of the solution therein whereby the solution is forced from the pump chamber through pipe 15, and as the check valve 17 prevents its return to the absorber A it passes through check valve 18 into, the large outer coil 19 of the heat exchang'erH and through this coil into the interior of the solution tank 2. As the solution passes from the pump chamber of the pump P its level lowers so that the float descends and operates the switch to close the valve 13 and open valve 14 whereupon the pressure of the gasified refrigerant passes through pipe 24 to the bottom absorber, discharges into the solution contained therein and also a portion discharges through the small orifice 21 into the spray issuing from the nozzle 22. As

the pressure within the pump chamber of pump P and the interior of the absorber equal- .izes the increased volume of the solution in the absorber causes the level to rise in the pump untilthe switch again opens valve 13 and simultaneously closes valve 14.

From the above it is seen that the action of the pump is intermittent and during the time the volume of the solution is increased as it absorbs the gaseous refrigerant that portion of the solution within the larger outer coil 19 of the heat exchanger H is being preheated so that when the float operates to allow the pressure of the vaporized refrigerant to force another charge of the solution I into the bottom of coil 19, the preheated so-' lution contained thereabove will be forced thru the coil into the solution tank, at the same time the pressure within the solution I tank is continuously discharging a certain .portion of the solution from the bottom of the is continuous and without the loss of either solution or refrigerant.

While the embodiment of this invention above described employs an electric heating element 4, it is to be understood that any type of heating device may be employed without departing from the scope of this invention.

Figures 4 and v illustrate a slight modification, and referring to Figure 4, a supplemental absorber B is shown, the top of which communicates by pipe 26A with the bottom of absorber A and the upper portion of absorber A communicates by means of pipe 27 with the top of the supplemental absorber B, whereby the level of the solution and the pressure above the solution in both absorber A and supplemental absorber B will be equalized. The pipe 24 from the top of the pump P to the absorber A communicates by means of pipe 28 with the bottom of the supplemental absorber B below a perforated bafiie plate 29'therein. The pipe 28 is connected to the pipe 24 between the valve 14 and absorber A. A valve 30, of the type illustrated in Figure 5, is interposed in the pipe 24 between its connection to the pipe 28 and the absorber A.

The valve 30 is formed with a partition 31,

having a seat therein for a ball 32, which is normally held by a spring 33 to rest upon a tubular projection 34, clearing the valve seat in the partition 31 so that there is a communication therethrough. The tubular portion 34, is provided with a plurality of openings,

35, forming a means of communication befrigerant entrapped above the solution level in the pump P being under .pressure rushes thru pipe 24 and enters the valve 30, passing through apertures, 35, will seat the ball 32 upon the partition 31 so that the gaseous refrigerant then passes by way of pipe 28 to the bottom of the supplemental absorber B and bubbles up through the solvent therein and such gas as is not absorbed will pass by the way of pipe 27 into the absorber A. When the pressure in the pump P approaches equalization with that within the absorber A, the

spring, 33, will depress the ball, 32, so that the pipe 24 will be in open communication between the pump P and absorber A. The bottom of supplemental absorber B is connected by pipe 16 to the heat exchanger and to the pump P by the pipe 15 in the same manner as shown in Figure 1.

It is preferable to provide in pipe 28 a restricted portion, 36, as shown, whereby, when the valve 14 is open, the gaseous refrigerant will be reduced in pressure before it enters the absorber B.

By the provision of the supplemental absorber, said absorber receives most of the gaseous refrigerant under pressure from the pump P, and the absorber, A receives substantially only the gaseous refrigerant from the cooling unit C.

What I claim is:

1. A refrigerating system including a gaseous refrigerant and a liquid solvent, an absorber, a still, a condenser, a cooling unit, means conducting the refrigerant from the cooling unit to the absorber, means conducting the solution from the absorber to the still including a chamber in communication with the solution in the absorber and the still, and in communication with the pressure side of the still and with the absorber,'valves in said latter communications, a float in the chamber adapted to alternately close one valve and open the other in accordance with the level of the solution in the chamber to admit pressure from the still intermittently to convey the solution from the chamber to the still and alternately to admit the gaseous refrigerant 2. A refrigerating system including a gaseous refrigerant and a liquid solvent, an absorber, a still, a condenser, a cooling unit, means conducting therefrigerant from the cooling unit to the absorber, means conducting the solution from the absorber to the still including a chamber in communication with the solution in the absorber and the still, and in communication with the pressure side of the still and with the absorber, valves in said latter communications, a float in thechamber adapted to alternately close one valve and open the other in accordance with the level tween pipe 24 and the under side of the ball 2 of the solution in the chamber to admit pres- 65 When the valve 14 opens the gaseous resure from thg still intermittently to convey the solution from the chamber to the still and alternately to admit the gaseous refrigerant under pressure from the chamber to the absorber and a rent in said communication above the surface of the Solution therein.

3. A refrigerating system including a gaseous refrigerant and a liquid solvent, an absorber, a still, a condenser, a cooling unit, means conducting the refrigerant from the cooling unit to the absorber, means conductin g the solution from the absorber to the still including a chamber in communication With the solution in the absorber and the still, a

(heck valve 1n sald communlcatmns prevent- 1 mg return of solution to absorber, and 1n communication with the pressure side of the still and with the absorber, valves in said latter communications, :1 float in the chamber adapted to alternately close one valve and open the other in accordance with the level of the solution in the chamber to admit pressure from the still intermittently to convey the solution from the chamber to the still, a check valve preventing return of solution from still to said chamber and alternately to admit the gaseous refrigerant under pressure from the chamber to the absorber below the surface of the solution and a vent in said communication above the surface of the solution therein.

GLENN F. ZELLHOEFER. 

